Patients will complete a number of questionnaires at baseline and undergo quantitative sensory testing (QST) as well as complete a handheld electronic diary PDA throughout the entire 10 weeks of the study. Patients will be evaluated by a physician and receive a complete history and physical. Radiological studies will be consulted to confirm diagnosis. All subjects who consent to participate in this study will be started on or converted to milnacipran if they are currently taking an SSRI, buproprion, or a TCA. This will be done over a 1 to 2 week period of gradually weaning the antidepressant and escalating milnacipran. All other adjuvant medication will remain constant through the course of the 10-week trial. Efforts will be made to recruit at least 40% of the patients (N= 24) who are not taking opioids for pain.